Cord lock for venetian blinds



Jan. 12, 1943. H. K. LoRENTzEN 2,308,291" @ORD LOCK Fon-VENETIAN BLINDs Filed Dec. 31,'v 1940 v J INVENTOR miforzzzfzz, BY A v Arm/f frs Patented Jan. l2, 1943 ooan Loon Fon vaNETrAN BLINDS Hans K. Lorcntgen, Montclair, N. J., assigner to Lorentzen HardwareMfg. Corp., New York, N. Y., a corporation of New Ir'orkv .Original application September 21, 193.8, ySerial No. 230,900; Divided and this application Der cember 3,1, 1940, Serial No. Ilflggl 4 Claims.

This invention relates to blind cord locks. This application is a d iyision of my copending application, S. N. 230,900, nled September 21,

1938, for Head-bar organization for Venetian blinds.

An object oi the present invention is to provide a cord lock for Venetian blinds of such construction `that a cord engaging dog is mounted to have the end of the dog press the cord against a part of a housing supporting the dog together with lmeans for limiting the degree ,of movement of the dog into locking position.

Another object of the invention is to provide a cord lool; so constructed Lthat a. dog associated with a pulley can move to press into locking engagement with cord below the `,pulley and also into braking relation tothe cord and the pulley.

A further object of the invention is to provide a cord lock so constructed that a dog mounted in a housing has one end thereof engageable with vertical expanses of cord passing through the housing and has another part thereof engageable with eXpanses of cord passing around a pulley in the housing.

Other features, objects and advantages of the invention will be apparent by reference to the following detailed description of the accompanying drawing wherein Fig. 1 is an end elevation of a cord locking device, such device being shown as being associated with a sheet metal head-bar construction, and

Fig. 2 is a section taken substantially on the line 2 2 of Fig. 1.

Referring now to the drawing IE! indicates generally a metallic head-bar organization which of itself forms` no part of the present invention. Only a fragment of one end of the head-bar has been shown in the drawing.

The cord lock device constituting the present invention is made up of a sheet metal housing,

indicated generally at l', and comp-rising two side walls I2 and IL', connected in spaced relation by an intermediate wall I5, the walls being integral. This intermediate wall can either be straight or can be bowed outwardly as is customary in devices of this character. A plate Il is secured in suitable fashion to edges of the side walls l2 and I, and, in the illustration, is secured to parts of the head-bar for assembly purposes. The wall l5 extends from a point below the top of the walls I2 and I4 to the bottom termination of these walls, as is shown clearly in the drawing, and the actual bottom of the wall I5 can be flared outwardly a slight amount as 55 shown at li. 1A sulla' l? is mounted .fer reta tien between the Side Walls 1.2mm i4 with ,a per@ ef the nella .eiieediag @validly beyond the lwal-.l I5 and the remaining part .of .the pulley exteeeing'inwerdlv reatire i0 this Wall! aber member 1.6 is ,mowed above the pulley t0 limit upward moienrilef 99rd? i9 rasees .aieundtlie pulley. y

v'A/dog member indicated generally at 2 0 .is p ivotally mounted between the plaies i2 and I4, such dog' member `being made iup of L.two side walls ,207 -and an .intermediate .connecting wall 2l This .Cenifeqtil Well" 25| -fia's e terminal wenn .22 beit @verlange i@ theme11 Part 0f the Wall- The end of Ithel ,term'inafl'portion 22 'can 'be straight@ ,caii `te provided'wiui ,teeth 'in die manner shown injmy Patent No; 2,075,214.

The dog 24) is soA positioned relativeto the wall I5 andthe'pullv .Ilth can,cooperate with `meseplanas 'angtwgith the .tores ,is to catania locking ofthe corda'gairist movement'in amanner more efficient than has been possible with prior art devices. By reference to Fig. 2, it will be noted that when the dog is moved into locking engagement cooperating with the parts, the end of the angular portion 22 of the dog presses the vertical expanses of the cord I9 against the wall l5. At the same time the upper surface of this angular part 22 presses against the cords I9 to bind them against the pulley Il. In this manner the dog acts not only to lock the cord against the wall I5 but also serves to simulate a brake pressing the cords against the pulley. The pulley, likewise in association with the cords,

serves as a stop to limit clockwise rotation of the dog about its pivot. Thus the present arrangement provides a device in which the lift cords for a blind passing over a pulley and normally stressed to move upwardly, so far as vertical expanse is concerned, are locked against such movement with a double action but at the same time the locking member is restrained against an extreme movement which might injure the cord, particularly if the end of the locking member is serrated or provided with teeth as is common practice. The kpulley also has the function of changing direction of movement of the lift cords so that they are readily accessible to an operator.

The device shown herein, while being illustrated as being mounted in an angular position relative to a metallic head-bar is capable of being used in connection with head-bars of other construction and materials. The device as shown is secured to the plate Il by having tongues thereof passing through openings in this plate and then staked thereto as shown at 30. Obviously the locking device can be associated at any desired angle and in any suitable relation to any type of head-bar, for which purpose it may be desirable to supply a closing Wall member of different coniiguration to take the place ofthe plate Il. y From the foregoing it will be seen that the present invention provides an improved cord lock of double action versatility and accordingly it is to be understood that the device is not to be limited to the illustrated embodiment but only by the scope of the following claims.

What is claimed is:

1. In a Venetian blind a cord lock comprising a housing having as part thereof an abutment wall, a pulley rotatably mounted in said housing above said abutment wall, and a dog pivotally mounted in the housing, the end of said dog being movable to engage cord passing between the end of the 'dog and the abutment wall and around the pulley to press the cord rmly against said abutment wall, said dog having a length greater than the distance between the axis of movement of the dog and the periphery of the pulley eective to press the cord against the pulley when the cord is also pressed against the abutment wall.

2. In a Venetian blind a cord lock comprising a housing having as part thereof an abutment wall, a pulley rotatably mounted in said housing above said abutment wall, and a dog pivotally mounted in the housing, the end of said dog bethe periphery of the 'pulley effective to bind said cord between said portion of the dog and said pulley when the cord is pressed against the abutment wall by the end of the dog.

3. In a Venetian blind a cord lock comprising a housing having as part thereof an abutment wall, a pulley rotatably mounted in said housing above said abutment wall, and a dog pivotally mounted in the housing, the end of said dog being movable to enga-ge cord passing between the end of the dog and the abutment wall and around the pulley to press the cord rmly against said abutment wall, said dog having a substantially iiat portion adjacent the end to press the cord against the pulley at the same time the cord is pressed against the abutment wall by the end of Ythe dog.

4. In a Venetian blind cord lock having a housing which the cords enter from one direction and leave in another direction, a pulley in the housing over which the cords pass to change direction, and a pivotal locking dog in the housing, the housing having an abutment wall, one end of the Wall being adjacent to the pulley and the wall extending approximately in the direction of the cords leaving the housing; the improvement which comprises: the dog having a locking nose which moves toward said abutment wall and a locking portion which moves toward the pulley when the dog moves to locking position, the spacing between said nose and said wall in locking position being less than the cord thickness when the spacing between said locking portion and said pulley is approximately equal to the cord thickness, whereby the pulley limits the movement of said nose toward said wall and the cord is locked both against said wall and said pulley.

HANS K. LORENTZEN. 

